Simulation of a zero energy office building in Egypt with a photovoltaic integrated shading system

The zero energy building (ZEB) concept mainly depends on the dual-nature of the building attached photovoltaics systems acting as active elements for energy generation as well as shading elements for energy savings. Previous studies have shown that the maximum energy savings occur when the internal heat gains and the internal lightings consumption are reduced and also thermal insulating materials are used in building construction. Our study aims to achieve a ZEB under Egyptian climatic conditions using photovoltaic integrated shading (PVIS) systems. This is done by simulating an office building using thermal-insulation layers in wall and roof construction. Moreover, a concept is applied through using the PVIS system on windows to act as an energy generation and energy saving element. Several simulation scenarios were conducted using Sketchup and EnergyPlus software while testing the effect of using PVIS as well as the effect of having insulation layers. Results show that the best annual net energy was generated in the case of the office model with PVIS system at a tilt angle of 60 deg and a projection factor 0.7 with air conditioning set at 21°C for heating and 26°C for cooling with glass wool insulation layers with a thickness of 0.1 m (double thickness) on the walls, and an extruded polystyrene insulation layer with thickness 0.11 m (double thickness) on the roof. This resulted in an annual monetary savings of 235%. Moreover, for all cases, the annual energy consumption, the annual net site energy, and the annual heating and cooling consumptions decrease with increasing the insulation layer thickness. The percentage annual energy savings were in the range of 50% to 80% depending on the test conditions, while the percentage annual monetary savings were in the range of 80% to 235%.